// SPDX-License-Identifier: GPL-2.0+
/*
* Uclass for EFI drivers
*
* Copyright (c) 2017 Heinrich Schuchardt
*
* For each EFI driver the uclass
* - creates a handle
* - installs the driver binding protocol
*
* The uclass provides the bind, start, and stop entry points for the driver
* binding protocol.
*
* In bind() and stop() it checks if the controller implements the protocol
* supported by the EFI driver. In the start() function it calls the bind()
* function of the EFI driver. In the stop() function it destroys the child
* controllers.
*/
#include <efi_driver.h>
/*
* Check node type. We do not support partitions as controller handles.
*
* @handle handle to be checked
* @return status code
*/
static efi_status_t check_node_type(efi_handle_t handle)
{
efi_status_t r, ret = EFI_SUCCESS;
const struct efi_device_path *dp;
/* Open the device path protocol */
r = EFI_CALL(systab.boottime->open_protocol(
handle, &efi_guid_device_path, (void **)&dp,
NULL, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL));
if (r == EFI_SUCCESS && dp) {
/* Get the last node */
const struct efi_device_path *node = efi_dp_last_node(dp);
/* We do not support partitions as controller */
if (!node || node->type == DEVICE_PATH_TYPE_MEDIA_DEVICE)
ret = EFI_UNSUPPORTED;
}
return ret;
}
/*
* Check if the driver supports the controller.
*
* @this driver binding protocol
* @controller_handle handle of the controller
* @remaining_device_path path specifying the child controller
* @return status code
*/
static efi_status_t EFIAPI efi_uc_supported(
struct efi_driver_binding_protocol *this,
efi_handle_t controller_handle,
struct efi_device_path *remaining_device_path)
{
efi_status_t r, ret;
void *interface;
struct efi_driver_binding_extended_protocol *bp =
(struct efi_driver_binding_extended_protocol *)this;
EFI_ENTRY("%p, %p, %ls", this, controller_handle,
efi_dp_str(remaining_device_path));
ret = EFI_CALL(systab.boottime->open_protocol(
controller_handle, bp->ops->protocol,
&interface, this->driver_binding_handle,
controller_handle, EFI_OPEN_PROTOCOL_BY_DRIVER));
switch (ret) {
case EFI_ACCESS_DENIED:
case EFI_ALREADY_STARTED:
goto out;
case EFI_SUCCESS:
break;
default:
ret = EFI_UNSUPPORTED;
goto out;
}
ret = check_node_type(controller_handle);
r = EFI_CALL(systab.boottime->close_protocol(
controller_handle, bp->ops->protocol,
this->driver_binding_handle,
controller_handle));
if (r != EFI_SUCCESS)
ret = EFI_UNSUPPORTED;
out:
return EFI_EXIT(ret);
}
/*
* Create child controllers and attach driver.
*
* @this driver binding protocol
* @controller_handle handle of the controller
* @remaining_device_path path specifying the child controller
* @return status code
*/
static efi_status_t EFIAPI efi_uc_start(
struct efi_driver_binding_protocol *this,
efi_handle_t controller_handle,
struct efi_device_path *remaining_device_path)
{
efi_status_t r, ret;
void *interface = NULL;
struct efi_driver_binding_extended_protocol *bp =
(struct efi_driver_binding_extended_protocol *)this;
EFI_ENTRY("%p, %pUl, %ls", this, controller_handle,
efi_dp_str(remaining_device_path));
/* Attach driver to controller */
ret = EFI_CALL(systab.boottime->open_protocol(
controller_handle, bp->ops->protocol,
&interface, this->driver_binding_handle,
controller_handle, EFI_OPEN_PROTOCOL_BY_DRIVER));
switch (ret) {
case EFI_ACCESS_DENIED:
case EFI_ALREADY_STARTED:
goto out;
case EFI_SUCCESS:
break;
default:
ret = EFI_UNSUPPORTED;
goto out;
}
ret = check_node_type(controller_handle);
if (ret != EFI_SUCCESS) {
r = EFI_CALL(systab.boottime->close_protocol(
controller_handle, bp->ops->protocol,
this->driver_binding_handle,
controller_handle));
if (r != EFI_SUCCESS)
EFI_PRINT("Failure to close handle\n");
goto out;
}
/* TODO: driver specific stuff */
bp->ops->bind(controller_handle, interface);
out:
return EFI_EXIT(ret);
}
/*
* Remove a single child controller from the parent controller.
*
* @controller_handle parent controller
* @child_handle child controller
* @return status code
*/
static efi_status_t disconnect_child(efi_handle_t controller_handle,
efi_handle_t child_handle)
{
efi_status_t ret;
efi_guid_t *guid_controller = NULL;
efi_guid_t *guid_child_controller = NULL;
ret = EFI_CALL(systab.boottime->close_protocol(
controller_handle, guid_controller,
child_handle, child_handle));
if (ret != EFI_SUCCESS) {
EFI_PRINT("Cannot close protocol\n");
return ret;
}
ret = EFI_CALL(systab.boottime->uninstall_protocol_interface(
child_handle, guid_child_controller, NULL));
if (ret != EFI_SUCCESS) {
EFI_PRINT("Cannot uninstall protocol interface\n");
return ret;
}
return ret;
}
/*
* Remove child controllers and disconnect the controller.
*
* @this driver binding protocol
* @controller_handle handle of the controller
* @number_of_children number of child controllers to remove
* @child_handle_buffer handles of the child controllers to remove
* @return status code
*/
static efi_status_t EFIAPI efi_uc_stop(
struct efi_driver_binding_protocol *this,
efi_handle_t controller_handle,
size_t number_of_children,
efi_handle_t *child_handle_buffer)
{
efi_status_t ret;
efi_uintn_t count;
struct efi_open_protocol_info_entry *entry_buffer;
efi_guid_t *guid_controller = NULL;
EFI_ENTRY("%p, %pUl, %zu, %p", this, controller_handle,
number_of_children, child_handle_buffer);
/* Destroy provided child controllers */
if (number_of_children) {
efi_uintn_t i;
for (i = 0; i < number_of_children; ++i) {
ret = disconnect_child(controller_handle,
child_handle_buffer[i]);
if (ret != EFI_SUCCESS)
return ret;
}
return EFI_SUCCESS;
}
/* Destroy all children */
ret = EFI_CALL(systab.boottime->open_protocol_information(
controller_handle, guid_controller,
&entry_buffer, &count));
if (ret != EFI_SUCCESS)
goto out;
while (count) {
if (entry_buffer[--count].attributes &
EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) {
ret = disconnect_child(
controller_handle,
entry_buffer[count].agent_handle);
if (ret != EFI_SUCCESS)
goto out;
}
}
ret = EFI_CALL(systab.boottime->free_pool(entry_buffer));
if (ret != EFI_SUCCESS)
printf("%s(%u) %s: ERROR: Cannot free pool\n",
__FILE__, __LINE__, __func__);
/* Detach driver from controller */
ret = EFI_CALL(systab.boottime->close_protocol(
controller_handle, guid_controller,
this->driver_binding_handle, controller_handle));
out:
return EFI_EXIT(ret);
}
static efi_status_t efi_add_driver(struct driver *drv)
{
efi_status_t ret;
const struct efi_driver_ops *ops = drv->ops;
struct efi_driver_binding_extended_protocol *bp;
debug("EFI: Adding driver '%s'\n", drv->name);
if (!ops->protocol) {
printf("EFI: ERROR: protocol GUID missing for driver '%s'\n",
drv->name);
return EFI_INVALID_PARAMETER;
}
bp = calloc(1, sizeof(struct efi_driver_binding_extended_protocol));
if (!bp)
return EFI_OUT_OF_RESOURCES;
bp->bp.supported = efi_uc_supported;
bp->bp.start = efi_uc_start;
bp->bp.stop = efi_uc_stop;
bp->bp.version = 0xffffffff;
bp->ops = drv->ops;
ret = efi_create_handle(&bp->bp.driver_binding_handle);
if (ret != EFI_SUCCESS) {
free(bp);
goto out;
}
bp->bp.image_handle = bp->bp.driver_binding_handle;
ret = efi_add_protocol(bp->bp.driver_binding_handle,
&efi_guid_driver_binding_protocol, bp);
if (ret != EFI_SUCCESS) {
efi_delete_handle(bp->bp.driver_binding_handle);
free(bp);
goto out;
}
out:
return ret;
}
/*
* Initialize the EFI drivers.
* Called by board_init_r().
*
* @return 0 = success, any other value will stop further execution
*/
efi_status_t efi_driver_init(void)
{
struct driver *drv;
efi_status_t ret = EFI_SUCCESS;
/* Save 'gd' pointer */
efi_save_gd();
debug("EFI: Initializing EFI driver framework\n");
for (drv = ll_entry_start(struct driver, driver);
drv < ll_entry_end(struct driver, driver); ++drv) {
if (drv->id == UCLASS_EFI) {
ret = efi_add_driver(drv);
if (ret != EFI_SUCCESS) {
printf("EFI: ERROR: failed to add driver %s\n",
drv->name);
break;
}
}
}
return ret;
}
static int efi_uc_init(struct uclass *class)
{
printf("EFI: Initializing UCLASS_EFI\n");
return 0;
}
static int efi_uc_destroy(struct uclass *class)
{
printf("Destroying UCLASS_EFI\n");
return 0;
}
UCLASS_DRIVER(efi) = {
.name = "efi",
.id = UCLASS_EFI,
.init = efi_uc_init,
.destroy = efi_uc_destroy,
};